Encystation of Entamoeba invadens IP‐1 Is Induced by Lowering the Osmotic Pressure and Depletion of Nutrients from the Medium1
- 1 November 1986
- journal article
- research article
- Published by Wiley in The Journal of Protozoology
- Vol. 33 (4), 522-525
- https://doi.org/10.1111/j.1550-7408.1986.tb05655.x
Abstract
Trophozoites of Entamoeba invadens IP-1 can be induced to encyst in simple solutions composed of semipermeable constituents (buffer, salts, or sugars) provided that their osmotic pressure is in the range of 60-160 mosmol/kg. Optimal yield of mature cysts was obtained when the osmotic pressure of the medium was 110 mosmol/kg. Encystation could be obtained in the absence of serum although higher yields were obtained in its presence. No difference in the yield of mature cysts was found when either dialyzed or full serum was used. High yields of encystation were obtained (> 70%) in the presence of 5% serum in solutions of NaCl, KCl, or MgSO4, suggesting that the mechanism of encystation is not induced via sodium or potassium channels. Cysts were obtained in the presence of 72 mM glucose, indicating that depletion of a carbon source is not the only requirement for encystation. A rapid change in the density of the Entamoeba cells was observed upon transfer of trophozoites (density 1.061-1.073 g/ml) from growth medium to the low osmotic pressure encystation solutions. Within the first 2 min their density decreased (to 1.050 g/ml), but it soon increased, reaching within 30 min a density higher than 1.120 g/ml. As the encystation process continued to completion, the density of the cells gradually decreased, the mature cysts reaching a density of 1.049-1.061 g/ml.This publication has 16 references indexed in Scilit:
- Changes in cell surface proteins and glycoproteins during the encystation of Entamoeba invadensMolecular and Biochemical Parasitology, 1985
- Entamoeba invadens and E. histolytica: Separation and purification of precysts and cysts by centrifugation on discontinuous density gradients of percollExperimental Parasitology, 1983
- A new medium for the axenic cultivation of Entamoeba histolytica and other EntamoebaTransactions of the Royal Society of Tropical Medicine and Hygiene, 1978
- Survival of Entamoeba and related amoebae at low temperature—I. Viability of Entamoeba cysts at 4°CInternational Journal for Parasitology, 1974
- ULTRASTRUCTURE OF BACTERIZED AND AXENIC TROPHOZOITES OF ENTAMOEBA HISTOLYTICA WITH PARTICULAR REFERENCE TO HELICAL BODIESThe Journal of cell biology, 1970
- The morphology, formation and development of cysts ofEntamoebaParasitology, 1969
- studies on Entamoeba invadens Rodhain, 1934, in vitro, and its relationship to some other species of EntamoebaParasitology, 1955